Cutting mill

ABSTRACT

A cutting mill with a horizontally disposed cutting rotor receiving pieces of plastic material from a vertically disposed input chute and pieces of material of a different size and shape from an upwardly inclined charging chamber. This chamber is disposed to extend through a lateral wall of the machine located on an upwardly pivotal part of the machine housing.

finite tates Patent 1191 Lehr 14 1 May 28, 19 74 1 1 CUTTHNG MILL 1,752,902 4 1930 Farner 241/186 R ux I 3,182,919 5/1965 Geer1ings.... 241/186 R X [75] lnvemor- Lei, Gelnhdusen, Germany 3,236,723 2/1966 Whiteside 241/224 x [73] Assigneet C0nduX wel-k Wolfgang bei Hanan 3,516,613 6/1970 Gilbert 241/189 R Germany 3,608,841 9/1971 Wagender 241/189 R [22] Flled: June 1972 Primary ExaminerGranville Y. Custer, Jr. [21] Appl. No.: 266,133 Assistant Examinerl-loward N. Goldberg Attorney, Agent, or FirmSpencer & Kaye [30] Foreign Application Priority Data July 2, 1971 Germany 2133086 [57] ABSTRACT [52] CL 241/224 241/277 A cutting mill with a horizontally disposed cutting [51] In! CL liozc 4/12 rotor receiving pieces of plastic material from a verti- [58] Field 'g l R 220 cally disposed input chute and pieces of material of a "iii 222 5 different size and shape from an upwardly inclined charging chamber. This chamber is disposed to extend [56] References Cited through a lateral wall of the machine located on an UNITED STATES PATENTS upwardly pivotal part of the machine housing.

1,171,747 2/1916 Newhouse 241/189 R 4 Claims, 1 Drawing Figure 1 e I l l l 1 Q 5 k i 19 1 1B .3 I0 8 I BACKGROUND OF THE INVENTION The present invention relates to a cutting mill for granulating plastic pieces and is of the type having a horizontally disposedcutting rotor and a vertically disposed input chute. The' housing of the mill includes a stationary part and a movable part meeting along a separating line which passes through the rotor axis and which is arranged at an acute angle with respect to a horizontal plane. The upper, movable, part of the housing can be swung open about a pivot axis and a drive motor as well as the rotor shaft bearing are fastened to the upper housing part so that the motor and rotor also act as rocker assembly for the pivotal upper part.

Such a machine is known and is particularly well suited for granulating bulky platic pieces. The division of the machine housing along an oblique angle and the fact that motor and rotor are fastened to the pivotal upper housing part result in substantial advantages with respect to maintenance and cleaning of the machine.

Cutting mills are also known which are particularly designed for the comminution of tubular or rod-shaped material. These machines are provided with a horizontally disposed input chute andare by nature not suited for the comminution of bulky pieces, due to the design of this chute.

Another type of cutting mill for granulating plastic pieces is disclosed in German Laid Open Pat. application (Offenlegungsschrift) No. 1,941,599. This machine is also designed for the comminution of tubular or rod-shaped plastic pieces. The patent application describes a plurality of embodiments which all have in common the significant feature of at least one pivotal charging chamber. This charging chamber is pivoted away for filling and is placed into another plane for discharging in order to facilitate the delivery of material. A further feature is that the charging chamber, in the loading position, is closed toward the grinding chamber of the machine and in the discharging position it is open toward this grinding chamber.

All of the above-described cutting mills for granulating plastic waste pieces are either suited for bulky material or for tubular or rod-shaped material, but not for both. Because the machines are of a special design to accommodate the shape of the material to be processed a particular machine can be used both for bulky and tubular or rod-shaped pieces only when an appropriate precomminution is effected for the latter type of pieces.

' SUMMARY OF THE INVENTION Therefore it is the object of the present invention to provide a cutting mill of the above-identified type which is equally suited to granulate bulky, as well as tubular or rodshaped, plastic pieces.

This is accomplished with a cutting mill of the abovementioned type, according to the present invention, by providing, in the lateral wall of the upper housing part which is disposed in the direction of rotation of the rotor, a charging chamber for the tubular or rod-shaped material. This chamber is disposed to be upwardly inclined away from the horizontal so that such pieces will slide into the grinding chamber of the machine due to their own weight.

In a further embodiment of the present invention, a control flap is disposed in the charging chamber to control the effective cross-sectional area of the chamber in dependence on the load placed on the motor. The control flap causes the quantity of material fed into the machine to be always in the most favorable ratio to the possible cutting output of the machine. This flap is preferably controlled in such a manner that when plastic pieces are being fed in through the vertically disposed input chute, the entire cross section of the inclined charging chamber is closed.

For purposes of cleaning and maintenance the upper part of the machine is pivoted away, in a known manner, and the charging chamber is arranged on the side of the upper housing part so that it also performs this pivoting movement. Thus the same advantages as with the known machines are provided for this machine.

Flush with this lateral charging chamber, but not rigidly connected thereto, a loading device may be provided which can be designed, as desired, with respect to its axial extent and which supports longer pieces during the filling operation. The loading device will also permit filling of the cutting mill from a floor above the floor on which the machine is disposed.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a cross-sectional elevational view showing the upper and lower housing parts of a cutting mill according to the invention closed together in the operative position of the mill.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the FIGURE, the cutting mill, generally indicated at 1, has a housing, generally indicated at 2, consisting of an upper housing part 3 and a lower housing part 4. The upper housing part 3 has a vertically disposed input chute 9 as well as an arm 5 on which a motor 6 is fastened. A cutting rotor 7, on a shaft 7, is supported by the upper housing portion 3 through suitable bearings, not shown.

The upper housing part 3 can be pivoted about a pivot axis 8 by a hydraulic mechanism, generally indicated at 8, which is operatively connected between the upper and lower housing parts. Motor 6 and rotor 7 here form a rocker assembly, the motor constituting a counterweight facilitating the pivoting movement during pivoting up of the upper housing part 3. As previously mentioned, such a design is known as are the advantages of such an arrangement.

The upper housing part 3 is separated from the lower housing part 4 by a separating line 11 which extends at an acute angle with respect to a horizontal plane, and which passes through the axis of rotor shaft 7. The lateral wall of the upper housing part 3 which lies opposite the pivot axis 8 in the direction of rotation of the rotor, as indicated by the arrow, is provided with a charging chamber 10 for delivering tubular or rod-shaped mate rial to the machine. This chamber is upwardly inclined with respect to the horizontal plane and thus, as opposed to the vertical chute 9, extends generally laterally with respect to the cutting rotor 7. In this embodiment the charging chamber 10 is formed of walls 14 and 18.

Two fixed blades 12 and 13 are disposed in the plane of separation of the two housing parts. The lower end of the bottom slide surface on wall 14 of the charging chamber opens into the grinding chamber, generally indicated at 15, approximately in the area of fixed blade 13.

A control gate 16 is disposed in the charging chamber 10 to control the cross section of the charging chamber 10 in dependence on the load put on motor 6. This gate 16 is pivotally mounted, at 17, to wall 18 of chamber 10 and is operatively connected for movement with a hydraulic mechanism, generally indicated at 19. When plastic pieces are fed to the cutting mill 1 through the vertically disposed input chute 9 the control gate 16 closes the charging chamber 10. The load on motor 6 can be measured in any known manner and the measurement signal applied to control the movement of mechanism 16. The load on motor 6 could be determined by measuring the motor speed current or voltage. Examples of such motor load-dependent regulations of the feed control in comminutors are described, for example, in German Pat. No. 915,110 or 11.8. Pat. No. 3,459,378. It is noted that the material comminuted by virtue of the cooperation between the cutting rotor 7 and the stationary blades l2, 13 is removed from the grinding chamber 15 in any conventional manner.

The charging chamber 10 will be pivoted together with the upper housing part 3.

A'dvantageously a loading device which is not illustrated may be connected to the charging chamber 10 to be flush therewith and may be of any desireddesign with respect to its axial extent. This loading device, of course, does not take part in the pivoting movement of the upper housing part 3. The loading device is intended to support pieces of material which are particularly long and also permits loading the cutting mill 1 from a floor above that of the cutting mill.

The particular advantage of the present invention is that it is now possible with one cutting mill to granulate bulky plastic pieces as well as tubes and rods of this material in a single machine without any particular modifications being required. The new cutting mill according to the present invention thus performs a comminution function which previously required two special machines of respectively different construction.

It will be understood that the above description of the 4 present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

I claim:

1. In a cutting mill for granulating plastic pieces having a horizontally disposed cutting rotor, a vertically disposed input chute to receive plastic pieces, a housing composed of a lower part and an upper part divided along a separating plane passing through the axis of the rotor and extending at an acute angle with respect to the horizontal, the upper housing part being pivotal away from the lower housing part about a pivot axis, a drive motor, and a rotor shaft, both of which are supported by the upper housing part to constitute a rocker assembly, the improvement wherein the upper housing part comprises a lateral wall spaced from the pivot axis in the direction of movement of the periphery of the rotor within the upper housing part, said lateral wall being provided with means defining a charging chamber for receiving tubular and rod-shaped material and communicating with said rotor, said charging chamber being upwardly inclined away from said rotor.

2. An arrangement as defined in claim 1, further comprising means associated with said charging chamber for selectively blocking the passage of material through said charging chamber during the time the cutting mill receives pieces through the vertically disposed input chute.

3. An arrangement as defined in claim 2, wherein said means comprises a control gate disposed in said charging chamber.

4. An arrangement as defined in claim 1, further comprising oppositely disposed upper and lower fixed blades supported on the lower housing part, and disposed adjacent the plane of separation between the upper and lower parts of the housing, a grinding chamber adjacent to the rotor and to said lower fixed blade, and means defining a bottom slide surface of said charging chamber which opens, at its lower end, into said grinding chamber in the area of said lower fixed blade. 

1. In a cutting mill for granulating plastic pieces having a horizontally disposed cutting rotor, a vertically disposed input chute to receive plastic pieces, a housing composed of a lower part and an upper part divided along a separating plane passing through the axis of the rotor and extending at an acute angle with respect to the horizontal, the upper housing part being pivotal away from the lower housing part about a pivot axis, a drive motor, and a rotor shaft, both of which are supported by the upper housing part to constitute a rocker assembly, the improvement wherein the upper housing part comprises a lateral wall spaced from the pivot axis in the direction of movement of the periphery of the rotor within the upper housing part, said lateral wall being provided with means defining a charging chamber for receiving tubular and rod-shaped material and communicating with said rotor, said charging chamber being upwardly inclined away from said rotor.
 2. An arrangement as defined in claim 1, further comprising means associated with said charging chamber for selectively blocking the passage of material through said charging chamber during the time the cutting mill receives pieces through the vertically disposed input chute.
 3. An arrangement as defined in claim 2, wherein said means comprises a control gate disposed in said charging chamber.
 4. An arrangement as defined in claim 1, further comprising oppositely disposed upper and lower fixed blades supported on the lower housing part, and disposed adjacent the plane of separation between the upper and lower parts of the housing, a grinding chamber adjacent to the rotor and to said lower fixed blade, and means defining a bottom slide surface of said charging chamber which opens, at its lower end, into said grinding chamber in the area of said lower fixed blade. 